Well, this is a first! Sorry, I can’t think of any way to do this globally! The only thing that comes to mind would be a customized software app that would go through each preset, doing a search and replace the value for all mixers. I had Bernard Wong (subliminaleffect) create a special app to do this for something similar several years ago. Let me contact him again and ask him.

I don't see how it can be clipping the input to the motu. It gets limited by the Solaris output to the maximum digital level. So I expect it is clipping at the Solaris output. I doubt using another sound card will change anything. I think you just need to turn down the Solaris level internally, as you did. Unfortunately I don't know of any easy way to even out the preset levels. Some sound designers make their presets generally louder than other designers.

I use Solaris Digital Out to Hosa AES/EBU Converter, fixed everything.
Solaris Digital Out to XITE-1 AES/EBU Input.
It sounds bigger than straight 48k SP/DIF and you’ve noticed you’re volume knob won’t work using Digital.

I don't have AES ins on motu mk3. And i don't understand how it sounds bigger between two digital signals that are just getting converted? And are you saying it was clipping before you switched to this method?

I’m assuming it’s the Hosa converter.
But Hosa has 48k to 44.1k ADAT Converters that seemed to cut the signal.
I wanted a rack of TC Fireworx running at 44.1 w/o using Mutec Word Clock.
Try one of these if eBay has them used.
You can select 44.1 or 48k on the ADAT end of things.